Cooperative behavior cascades in human social networks

By James H. Fowler, Nicholas A. Christakis. Proceedings of the National Academy of Sciences of the United States of America, 2009

753 citations recorded by the source corpus.

Theoretical models suggest that social networks influence the evolution of cooperation, but to date there have been few experimental studies. Observational data suggest that a wide variety of behaviors may spread in human social networks, but subjects in such studies can choose to befriend people with similar behaviors, posing difficulty for causal inference. Here, we exploit a seminal set of laboratory experiments that originally showed that voluntary costly punishment can help sustain cooperation. In these experiments, subjects were randomly assigned to a sequence of different groups to play a series of single-shot public goods games with strangers; this feature allowed us to draw networks of interactions to explore how cooperative and uncooperative behaviors spread from person to person to person. We show that, in both an ordinary public goods game and in a public goods game with punishment, focal individuals are influenced by fellow group members’ contribution behavior in future interactions with other individuals who were not a party to the initial interaction. Furthermore, this influence persists for multiple periods and spreads up to three degrees of separation (from person to person to person to person). The results suggest that each additional contribution a subject makes to the public good in the first period is tripled over the course of the experiment by other subjects who are directly or indirectly influenced to contribute more as a consequence. These results show experimentally that cooperative behavior cascades in human social networks.

Subfields: Experimental and Cognitive Psychology, Safety Research, Sociology and Political Science

View Paper: https://www.semanticscholar.org/paper/91e3c2d10e64b9fb0c584666c7c25f8115fc9e3c

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Citations in the corpus

Social Networks and Cooperation in Hunter-Gatherers (2012, background): “Another is that people may influence the cooperative behaviour of their networks, as demonstrated in experimental studie”
Social Networks and Causal Inference (2013, background): “Internet- or lab-based experiments in which investigators themselves fix the network structure may prove an efficient and cost-effective means for studying network phenomenon (Centola 2010; Fowler and Christakis 2010).”
The Bright Side of Being Prosocial at Work, and the Dark Side, Too: A Review and Agenda for Research on Other-Oriented Motives, Behavior, and Impact in Organizations (2016, background): “…the presence of a single consistent contributor in a group can lead others to contribute and cooperate more (Weber & Murnighan, 2008), and group members’ contributions can spread up to three degrees of separation, “from person to person to person to person” (Fowler & Christakis, 2010, p. 5334).”
Beyond Altruism: Sociological Foundations of Cooperation and Prosocial Behavior (2015, positive): “In addition to unilateral giving behaviors, other work establishes how contributions to public goods can cascade through networks, inﬂuencing the behaviors of people b r a y on 06 / removed from the original contributor (Fowler & Christakis 2010). remains r o n L limited.”
Cooperation and Contagion in Web-Based, Networked Public Goods Experiments (2010, background): “Put another way, local reinforcement would imply that when an individual’s neighbors also interact with each other, they are in a better position to reinforce one another’s pro-social behavior, and so may be expected to resist “invasion” by defecting strategies better than when each neighbor…”
Predicting emerging social conventions in online social networks (2012, background): “In one of the seminal works on social diffusion, Christakis and Fowler find evidence for the spread of obesity [15] and cooperative behavior [23] through social networks (but see [18]).”
Empathy: a motivated account. (2014, background): “As reviewed above, empathy-positive social norms increase individuals’ willingness to empathize with outgroup members (Tarrant et al., 2009), and prosocial norms likewise induce personal generosity (Fowler & Christakis, 2010; Nook, Ong, Morelli, Mitchell, & Zaki, 2014).”
Is Oprah Contagious? Identifying Demand Spillovers in Online Networks (2012, neutral): “and recent studies (though conducted in other domains) on real-world networks with a Fowler and Christakis 2010; Friedkin 1983).”
Social Network Sensors for Early Detection of Contagious Outbreaks (2010, background): “…outbreak (flu) in a particular population (college students), it could potentially be generalized to other phenomena that spread in networks, whether biological (antibiotic-resistant germs), psychological (depression), normative (altruism),( 27 ) informational (rumors), or behavioral (smoking).”
Adaptation, Learning, and Optimization over Networks (2014, background): “They are also well-suited to model several forms of complex behavior exhibited by biological [16, 50, 131, 147] and social networks [15, 77, 92, 121, 230] such as fish schooling [188], prey-predator maneuvers [105, 171], bird formations [110, 119], bee swarming [12, 22, 125, 220], bacteria motility ”
Challenging the Norm of Self-Interest: Minority Influence and Transitions to Helping Norms in Work Units (2012, background): “As noted previously, scholars have begun to demonstrate that helping behaviors can spread from one individual to another (Fowler & Christakis, 2010; Weber & Murnighan, 2008), but little theory and research exist to provide a comprehensive explanation of the key mechanisms that underlie this dynamic…”